My present invention is a scribing tool having a retractable scratch awl. A principal object of the invention lies in the provision of a scratch awl which may be selectively extended and retracted so that it may be conveniently carried in ones pocket.

Another object of the present invention lies in the provision of a scribing tool which has a protective tubular housing within which the scribing element is initially contained and adapted to be extended from the housing a distance according to selection for use.

A further object of the invention lies in the provision of a scribing tool having mechanical means actuated by a manually rotatable thumb knob on the upper end of the tubular housing and operable to extend and retract the scribing element and having novel means conlining the thumb knob against axial movement from the end of the housing.

A still further object of the invention lies in the provision in a scribing tool of an improved scratch awl which is nearly `as long as the tubular housing of the scribing tool and therefore is capable of being extended a considerable distance when such case is found desirable.

In the accompanying drawings forming a part of this specification and in which like numerals are employed to designate like parts:

Figure 1 is a View in elevation of my improved scribing tool shown upon a slightly enlarged scale and having the scratch awl tip partially extended from the housing;

Figure 2 is a longitudinal vertical cross section of the scratch awl;

Figure 3 is a lateral cross section taken substantially on the plane indicated at line 3 3 of Figure 2;

Figure 4 is a lateral cross section taken substantially on the plane indicated at line 4 4 of Figure 2;

Figure 5 is an enlarged fragmentary View having portions broken away and showing a modified form of the scribing tool; and

Figure 6 is a perspective view showing an adaptor for association with the scribing tool of Figure 5.

Having reference now with a greater degree of particularity to the drawings, I have shown the scribing tool 10 as having an elongated tubular housing 12 which at its upper end is reduced and externally threaded at 14 from its upper end face 16 to a shoulder 1S downwardly spaced from the upper end face 16. At its lower end, the housing is provided with a reduced cylindrical bore 20 which is suiiiciently long to constitute ample bearing area to form a journal for supporting the lower end of the scribing element 22. Upwardly of and contiguous to the journal 20, I provide a concentric cylindrical bore 24 which has a circumference enlarged over that of the journal 20 and which constitutes an enlarged journal for the lower end of the drive tube 26.

The drive tube extends from the upper end face 16 through the tubular housing 12 and is journaled at its lower end in the enlarged journal 24. The drive tube 26 is provided with a longitudinally extending slot 28 for its "ice full length. At its upper end, the drive tube 26 is provided with a thumb knob 30 which inspection of Figure 2 will reveal has at its juncture with the drive tube 26 an annular peripheral ange 32. The circumferential size of the flange 32 is substantially identical to the circumerential size of the reduced and threaded upper end portion of the housing 12.

To coniine the drive tube 26 against axial movement out of the housing 12, I provide an internally threaded metallic sleeve 34 which has an inwardly projecting ange 36 at its upper end which deines an aperture 38 through which the major portion of the thumb knob 30 extends. The ange 36 is, however, in overlying relationship to the peripheral liange 32 of the thumb knob 30 and therefore prevents removal of the thumb knob and the drive tube 26 from the tubular housing 12.

The sleeve 34 preferably carries an integral pocket clip member 40, the use of which is identical to that of conventional pocket clips on pencils or pens.

The scratch awl 22 has a cylindrical rod-like body 42 which is only slightly shorter than the length of the tubular housing 12 and is provided with a sharp, preferably case-hardened scratching or scribing tip 44 at its lower end. At its upper end, the scratch awl has an integral radially disposed and longitudinally extending ridge 46 which is threaded on its outer face 48 and extends through the drive tube slot 28 to cooperate with the internal threads S0 of the tubular housing disposed between the enlarged journal 24 and the upper end face 16 of the housing 12 so that rotation thereby will advance and retract the scratch awl relative to the housing.

Attention is drawn to the fact that the scratch awl rod 42 is of suiicient length that it may be projected from the housing 12 a considerable distance. In actual practice, this extension equals substantially 41/2 inches from the lower end of the housing 12 to the scribing tip or point 44. It also may be positioned at any extended position intermediate its retracted position indicated by the dotted lines of the tip 44 as shown at 44a, and its fully extended position in accordance with manual selection as desired for the job at hand. Obviously, the extending and retracting movements of the scribing element 22 are effected by rotation of the thumb knob 30 which rotates the drive tube 26, causing the scribing element 22 to rotate and the interaction of the threads 48 on the ridge 46 and the internal threads 50 of the housing- 12 effect longitudinal movements of the scribing element.

The modified scribing tool shown in Figures 5 and 6 has a scratch awl 22 with the rod-like body 42 terminating in a scribing tip 44. At the end opposed to the scribing tip 44, the awl 22' is provided with a head 58 integral with the body but spaced therefrom by reduced extension 60. An adaptor 52 is provided with a longitudinally extending radially disposed ridge 46' which is threaded on its outer face 48' and has a recess at 54 to receive the head 58 and a vertically disposed slot 56 communicating with the recess 54 to receive the extension 60 as shown in Figure 5. This provides a device which is much more easily manufactured at less expense, since the scratch awl 22 may be manufactured with greater ease.

One skilled in metal fabrication or metal tool construction will readily see the numerous advantages and desirable objects of my present invention.

Having thus described my invention, I claim:

For use in a scribing tool body having an internally threaded bore containing a selectively rotatable longitudinally slotted drive tube for slidably receiving a scratch awl; a scratch awl comprising an elongated rod having a scratching point at one end and a head commensurate in cross sectional size and configuration to the rod at the opposed end and united therewith by means of a 'said 'adaptor extending beyond the periphery of said rod and Aadapted f'to slidalrily extend from the slot of said drivetube; and threads on the outer face of said ridge adapted to cooperate with the threads of the internally Vthreaded bore when said scratch awl and adaptor are disposed in said scribng tool body.